I don't claim any medical knowledge, or knowledge of this particular problem, so I won't offer advice on what to do about it, but if it turns out that a shim under your cleat is what's needed I would recomend you take your shoe and cleat to a machinist, and ask him to make you a cleat in the thickness you need. It should be a quick easy job for someone with the right tools. basically a small piece of aluminum with 2 holes drilled in it. No need to futz around with wedges that come loose, and it shouldn't cost an arm and a leg.